1. Field of the Invention
The present invention relates to a noncontact tonometer for measuring the intraocular pressure of a subject's eye.
2. Description of the Related Art
A previously proposed noncontact tonometer measures the corneal thickness of the eye after being aligned with the eye, flattens a section of the cornea by applying an air pulse to the cornea by a puffing means, determines the intraocular pressure on the basis of the pressure of the air pulse applied to the cornea, and corrects the measured intraocular pressure on the basis of the measured corneal thickness.
The corneal thickness is not uniform over the entire cornea and different sections of the cornea have different corneal thicknesses, respectively. Since the air pulse is applied to the cornea a little time after the measurement of the corneal thickness, it is possible that a section of the cornea to which the air pulse is applied differs greatly from a section of the same where the corneal thickness is measured due to a small involuntary movement of the eye during the interval between a puffing operation for applying an air pulse to the eye and a corneal thickness measuring operation for measuring corneal thickness. In such a case, incorrect data on the intraocular pressure will be obtained if the measured intraocular pressure is corrected by the measured corneal thickness.